1. Field of the Invention
The present invention relates to a thermoplastic elastomer composition having an excellent heat-bondability to various resins and metals and having a high rubbery elasticity, a good moldability and a high heat resistance. More particularly, the present invention relates to a partially crosslinked thermoplastic elastomer, which is formed by dynamically heat-treating a peroxide-crosslinking olefin copolymer rubber with an unsaturated carboxylic acid or a derivative thereof in the presence of an organic peroxide.
2. Description of the Prior Art
A thermoplastic elastomer has been known as an energy-saving and resource-saving substitute for a cured rubber.
As the thermoplastic elastomer of this type, there is known, for example, an olefinic thermoplastic elastomer comprising as the main component an ethylene/propylene/non-conjugated diene copolymer rubber. This thermoplastic elastomer is excellent in thermoplastic elastomer performances, but since the bondability to various resins or metals is insufficient, the application range of this thermoplastic elastomer is considerably limited.
Graft modification of the above-mentioned rubber component with maleic anhydride or the like has been tried for improving the bondability. In this case, the bondability is improved, but such a disadvantage as reduction of the rubbery elasticity, the moldability and the like cannot be avoided.
Namely, a thermoplastic elastomer which is excellent in such properties as rubbery elasticity and moldability and has an excellent bondability to various resins and metals has not been known.